We recommend you regularly change your dispenser batteries to keep it running optimally. 
PLEASE NOTE that in no circumstances should you use rechargeable batteries as they can lead to serious dispenser malfunction. 
The correct batteries to use are AA Alkaline batteries. 
Be sure to align the polarities correctly when installing, there is a diagram embossed on the inside of the dispenser. 

CLICK HERE to purchase batteries from the Ecomist store.